KNOXVILLE - Derek Dooley has never seemed like a sugar-coating type of person.

When asked how he felt about his University of Tennessee football team's depth situation, the Volunteers new coach didn't mince words.

"I'm terrified," he said.

And who could argue?

The Vols lost two starting defensive linemen, almost certainly for the entire season, before they donned full pads for the first time Sunday afternoon at Haslam Field.

Sophomore tackle Marlon Walls ruptured an Achilles one day after senior end Ben Martin suffered the same injury.

"Our Achilles heel so far has been our Achilles heel," Dooley said.

What's worse for the Vols, both defensive linemen went down in non-contact situations.

"They weren't doing anything. Basically, they were walking over a pad," Dooley said. "It happens. ACLs happen like that sometimes. I don't know. The first thing I said was, 'Did we do anything to contribute to it?' I don't know. I think a lot of times, in Ben's case, sometimes when you're fighting a lot of injuries, more things creep up elsewhere. Your body's always compensating. You think your back's a problem, but it's something else.

"Now, I don't know that. I'm not a doctor. I'm just a coach."

Walls is a less proven player than Martin, but end is one of the Vols' deepest positions. Tackle is certainly not.

Senior center Victor Thomas was moved back to defensive tackle - his original position - but now sophomore Montori Hughes is the team's only known commodity at that crucial position.

"I don't have a sense for what any of the D-tackles can do other than Montori right now," Dooley said. "Montori's a really good player. He plays with great reckless abandon out there. He's a competitor. He's got tremendous competitive fire.

"We need to get more guys like him."

Thomas is happy to try.

"I was excited to help the team out anyway I could," said Thomas, who was signed five years ago as a four-star recruit from Mississippi. "It was just another opportunity for me to get on the field. It was kind of odd in the beginning today. But once I got back into the rotation, it came back to me really quickly."

Thomas figures to battle junior Rae Sykes and sophomore Steven Fowlkes - who both played end last season - for a starting position.

Senior defensive end Gerald Williams liked what he saw from all three candidates Sunday.

"They're young, but they never quit," Williams said. "They're young, but they're on D-I scholarship just like everyone else here. We're just going to keep pushing on.

"We can't get down. Injuries are going to occur when you're dealing with football, so we've just got to step up. It's time for the next guy in line to step up for his opportunity.

"Big Vic coming back helps a lot. He's a natural D-lineman, as we saw today."

Some have suggested the Vols look at switching from the 4-3 base defense to a 3-4 base, but Dooley correctly noted that UT would actually need more big bodies for the switch.

The coach then joked that his staff might have to get even more creative than usual.

"You really need three big guys in a 3-4," he said. "In a 4-3, you need two big guys. You can get away with some lighter ends in a 4-3. If you go to a 3-4, you say, 'There's one less defensive lineman.' But you're adding one more big guy, because you're reducing them down.

"We're looking at going into a 2-5, maybe a 1-6. We're going to be the first team ever to employ a 1-6. The 1 better be a big guy; really big."

In all seriousness, though, the coach is clearly - and justifiably - concerned about his attrition-ridden roster.

"We don't have any depth anywhere," Dooley said. "We've had three guys who signed with us who aren't here. It hurts us, but that's what happens when you take high-risk guys. We don't like to do that, with academic risks. Here we are, but we had no choice. The last couple of weeks, we took a couple of risks.

"We have zero depth anywhere except on the training staff. We have the deepest training staff in the history of college football."

Other contacts for Wes Rucker are www.twitter.com/wesrucker and www.facebook.com/tfpvolsbeat.